It marks the fourth time in Serena’s career that the American has finished a season ranked No. 1 after 2002, 2009 and 2013. She’s also just the fifth player in WTA history to do it four or more times after Steffi Graf (who did it eight times), Martina Navratilova (seven times), Chris Evert (five times) and Lindsay Davenport (also four times).

“I love being No.1; I love being the best. But at the same time, I’m really glad I was able to get a Slam this year, which was really annoying for me that I wasn’t able to capture one before,” Serena said earlier this week.

Thanks to a set win by Simona Halep today, Serena remains alive in the WTA Finals in Singapore. Tomorrow the 4-time tournament champion will play good friend Caroline Wozniacki in the semifinals.

Serena celebrated the achievement by going with Wozniacki to a Mariah Carey concert:

Urgh Mariah Carey,cant stand that woman or her singing,which i compare to a cat been doctored,Muse,Blur,Oasis or Kings of Leon would be a better choice IMO,but thats just my taste as i love the dirty rocker indie type of music,anyway congrats to Caroline on a clean sweep,but stop been so damn friendly with Serena,and concentrate on trying to kick her but for a change,instead of it always been the other way around….

I’m shocked she’s only had year end #1 4 times, only 3 times before this. Wow. It really puts an exclamation point on just how sporadic her success has been. Seems like she’s been dominating for ten years, but obviously not so much.